1. Field of the Invention
The present invention relates to an IC card with additional terminals and a method of controlling the IC card.
2. Description of the Prior Art
Conventional connection terminals disposed in an IC card are based on ISO/DIS7816/2 standards. The connection terminals are eight in total and consist of power source terminals (Vcc and GND), a reference clock terminal (CLK), a reset signal terminal (RST), a data communication terminal (I/O), a power source terminal (Vpp) for writing data into a nonvolatile memory disposed inside the IC card, and two reserved terminals (RFUs). The reserved terminals (RFUs) are presently not used, and therefore, the remaining six terminals are used to connect the IC card to a terminal unit.
FIG. 1 is a view of a conventional IC card 1, and FIG. 2 is a view of the dimensions and positions of eight connection terminals C1 to C8 of the IC card 1. The connection terminals C1 to C8 are packaged in an IC module 2 in the IC card 1. The terminal C1 is a power source terminal (Vcc), C2 a reset signal terminal (RST), C3 a reference clock terminal (CLK), C4 a reserved terminal (RFU), C5 a power source terminal (GND), C6 a power source terminal (Vpp) for writing data into a nonvolatile memory, C7 a data communication terminal (I/O), and C8 another reserved terminal (RFU).
The connection terminals of the conventional IC card may be formed in various shapes as shown in FIG. 3.
The conventional IC card according to the ISO/DIS standards has only these eight connection terminals in total including the reserved terminal RFU (C8) that is presently not used and the single data communication terminal C7 (I/O). The data communication carried out through the data communication terminal C7 is of a start-stop synchronization type which is very slow in communication speed. For example, the conventional IC card takes several seconds to several minutes to start the data communication after it is inserted into a terminal unit. The use of only one data communication terminal not only delays the start of data communication but also hinders sufficient performance of CPU functions of the IC card.